Erasing device for type-writers.



IL I. SEDDON.

ERASING DEVICE FOR TYPE WRITERS.

APPLIGATIOH FILED :rnnzo, 191s.

L@83 @6fi, Patented Jan. 6, 1.914.

2 SHEBTSSKEET l.

H. I. SEDDON.

ERASING DEVICE FOR TYPE WRITERS.

APPLICATION FILED JAN. 20, 1913.

Patented J an. 6, 1914.

2 SHEETS-SHEET 2.

WITNESSES:

BY Wm A TTOB/VEV HARRY I. SEDDON, OF PORTLAND, OREGON.

ERASING DEVICE FOR TYPE-WRITERS.

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Specification of Letters Patent.

Application filed January 20, 1913. Serial No. 743,229.

To all whom it may concern:

Be it known that I, HARRY I. SEDDON, a citizen of the United States, residing at Portland, in the county of Multnomah and State of Oregon, have invented new and useful Improvements in Erasing Devices for Type-Writers, of which the following is a specification. Q

My invention has relation to a typewriting machine, and refers particularly to means for performing erasures of the matter printed on the machine.

The object of my invention is to provide a device of the above character of simple and inexpensive construction.

A further object is the provision of means whereby erasures may be made in the same manner that impressions of letters or characters are performed, and without the expenditure ofadditional labor.

With these objects in view my invention consists in the combinations and features hereinafter fully explained, concisely set forth in the appended claims, and illustrated in the accompanying drawings, of which:

Figure 1 shows, in side elevation, a unit of the key-lever and typebar system of a typewriting machine embodying the invention, Fig. 2 shows portions of Fig. 1 one larger scale, Fig. 3 illustrates the erasing head of my device very much enlarged, and Figs. 4 and 5 illustrate, on a large scale, further features the importance of which will readily appear on perusal of the following description.

The device I am about to describe adapts itself readily to any class of type-bar machine, and in Fig. -1 I indicate the outline of a front strike machine in order to show the relation of the erasing device to the ma chine. The machine frame is constructed in the usual manner to support a springheld key-lever l, which through the medium of a bell-crank mechanism 2 is connected to operate a pivoted bar 3. The inner end of this bar is identical with the remaining typebars of the machine, and its hanger 4 is mounted'on the segment 5 in the usual'manner. The outer end of the bar, on the other hand, is bifurcated, and an arm 6 is pivotally fixed in said bifurcation. The arm 6 carries, near its pivotal point, a, projection 7 which'engages the edge of the bar for the purpose of limiting the forward movement of the-arm on the bar. A suitable spring 8 is suspended between the arm and the bar and said spring serves to yieldingly retain the arm in its forward position, as clearly shown in the drawings. The outer end of the arm terminates in a head 9, and the latter carries on its face a plurality of transverse teeth 10. Said teeth may be made in any suitable manner so as to provide sharp cutting-edges for erasing purposes. Above the machine frame is mounted the usual platen 11, but as the various means of supporting such platen. for rotary and longitudinal movement relative to the frame are well known to those versed in the art, and as such means have no bearing on this description, the illustration of a mere outline of a platen carrying a sheet of paper is thought sufficient.

The operation of the device will now be described.

The printed character to be erased is first brought to the printing point of the platen. A depression of the finger-key of the keylever 1 causes the erasing bar 3 to swing toward the platen, and as the cutter head 9 is alined to correspond with the'type-ba-rs of the machine, the said head will strike the platen at the printing point. The moment the cutter-head strikes the platen, the arm 6 commences to swing outwardly against the tension of the spring 8 for the reason that.

the bar 3 has not reached the limit of its movement. In thus swinging the cutterhcad gradually rises relative to the printing point, as indicated in Fig. 2. In other words the cutter moves vertically along the surface of the paper on the platen, and during this movement it cuts very-lightly into the paper, sufficiently to cut out a portion of the paper and the character to be erased. A few taps (n the finger-key and a consequent repetition of this cutting operation removes a suflicient amount of paper to entirely obliterate the printed character, and a new impression may be made in the same spot. v

By referring to the drawing it is noticed that'the face of the cutter is curved, and this curve is so calculated relative to the swing of the cutter arm as to cut.,a space Patented Jan. 6, 1914.

substantially the height of the printed char acter. The number of finger-key depressions required in order to complete an erasure depends upon the tension of the spring 8 combined with the force of the blow delivered. That is to say, the stiffer the spring is, the more force is required to complete a stroke and the more effectively the cutter operates at each stroke.

It is well known that the depression of a type-writer key causes the platen to move longitudinally one space. This, of course, would be detrimental to the successful operation of the above described device, and it therefore becomes'necessary to provide means for preventing movement of the platen during the erasing operation. This may be accomplished in various ways, for instance as shown in Fig. 1. Underneath the key-levers is rotatably fixed a universal bail 14:, which in any suitable manner connects with the escapement of the machine (not shown). Every depression of the key causes-said bail to oscillate and therethrough to operate the escapement. The key-lever 1 is made with a notch 16 positioned directly above the universal bar 15. When said lever is depressed it fails to reach the said universal bar on account of the said notch, and

the platen thus remains stationary. Some machines, as for example the Remington typewriter, are made with a screw' fixed in the key-lever and positioned to strike the universal bar, and in such machines it is only necessary to remove said screw.

In Figs. 4 and 5 I show a modified form of cutter mechanism. The erasing bar 20 is made with a perforated head 21, and. in this head is mounted a circular cutter 22. It is noticed that the stem 23 of said cutter is made with spiral threads engaging corresponding threads of the perforation of the head. A suitable spring 24 serves to yieldingly retain the cutter in a projected position, and its forward movement is conveniently limited by a stop screw 25. When this cutter strikes the platen it is caused to recede into the head 21, and in thus receding it rotates, being compelled to follow the windings of the spiral threads. During this 'movement the cutter also rises slightly due to the curve the bar describes in approaching the printing point. A combined circular and vertical 'movement is thus obtained, by means of which an erasure is quickly performed. v

Inconclusion I wish to state that,.while I show and describe a toothed cutter made of suitable metal, because such cutter has been found very efficient, I can substitute a piece of eraser made of the usual india-rubber composition, but it is obvious that such eraser will not possess the wearing qualities of the metal cutter.

The key-lever above described is usually termed a silent or dummy key-lever. The erasing bar, on account of itsresemblance to and its position relative to the regular type-bars of the machine, conveniently be termed a type-bar having an erasing head in place of the usual type.

I claim:

1. In a typewriter, erasing means, said means including a silent key-lever, an erasing bar operatively connected thereto, and an erasing head yieldingly pivoted on said 2. In a typewriter, erasing means, said means including a silent key-lever, a bar mounted in the type-bar basket and alined with the type-bars, said bar having an arm yieldingly pivoted, and an erasing head on the outer end of said arm.

3. In a typewriter, a silent key-lever, key-lever connections, a bar mounted in the type-bar basket for o eration by said keylever, and an erasing ead on said pivoted bar, said head mounted to move vertically in striking the platen.

4. In a typewriter, a silent key-lever, a bar pivotally mounted in the type-bar basket, an erasing head on said bar, said bar operatively connected with said lever, and means whereby the said erasing head on striking the platen shifts vertically relative to the platen.

e 5 In a typewriter, erasing means, said means including an erasing member for contact with the platen, key-operated means for bringing said member into contact with the platen", and means whereby said member is given a rotating and a vertical movement on striking the platen.

6. In a typewriter, a bar having an erasing head alined to strike the printing point, and means actuated by the impact of the said head striking the platen for moving said head vertically relative to the platen.

7. In a typewriter, a key lever, a bar, an erasing head on said bar, and connections between said bar and lever, said head bein yieldingly fixed on the bar; so as to shi t vertically relative to the platen in striking.

8. In a typewriter, a bar, an erasing head mounted on the free end of said bar, yielding means for normally retaining said head in a forward position on the bar, the devices so related that the said head, in striking the platen, recedes, and in receding moves rotatively and vertically relative to the platen.

9. In a typewriter, a bar, means for operating said bar without spacing the platen, an arm pivoted on the free end of said bar, an erasing head on said arm, and-yielding means for holding said arm forwardly proje'cted, the devices so related as to cause the said head to rise'vertically on the platen in striking.

oeaeee 7 g 10. In a typewriter, a silent key-lever, and aflixed my signature in presence of subscriba bar unit carrying an erasing head, andl coning Witnesses. nections' between said levers and bar, said head yieldingly fixed; and so positioned as HARRY SEDDQN 5 to move vertical relatively to the platen on I Witnesses:

striking. DEWEY HOMER,

In testimony whereof, I have hereunto O. O. MARTIN. 

